1. Field of the Invention
The present invention relates generally to a connection member and a lead terminal seat structure with the connection member.
2. Description of the Related Art
A conventional lead terminal or solderless terminal has an insulation housing (generally made of plastic material) and leaf spring or metal piece enclosed in the insulation housing for pressing and electrically connecting with a lead inserted in the lead terminal. For example, U.S. Pat. No. 6,689,955 B2 entitled “connecting device with a connection spring operated by a cam” discloses a typical lead terminal.
Such lead terminal is inserted on a circuit board (such as a PC circuit board). The insulation housing of the lead terminal has multiple perforations. The leads extending from a machine or equipment can be inserted through the perforations into the housing. The housing defines a cavity in which the leaf spring or metal piece is mounted. The lead can be inserted into the cavity into electrical contact with the leaf spring or metal piece. The leaf spring or metal piece has a head end. After the lead is inserted into the housing, the head end holds the lead to prevent the lead from disconnecting from the leaf spring or metal piece or detaching from the insulation housing. A user needs to extend a tool such as a screwdriver into the housing to push the head end for releasing and disconnecting the lead from the leaf spring or metal piece. The metal piece has a pair of fine symmetrical pins for complementarily insert-connecting with the pins of the circuit board or the pins of another lead terminal.
It is troublesome for an operator to use the tool to release and disconnect the lead from the leaf spring or metal piece and detach the lead from the insulation housing. Therefore, in the above patent, a cam is disposed in the insulation housing in abutment with the leaf spring or metal piece. The cam has a lever section extending out of the housing. An operator can forcedly shift the lever to make the cam press the metal piece into contact with the lead or release the metal piece to free the lead.
The existent terminal seat includes a front casing and a rear casing made with molds. (The direction in which the lead enters the terminal seat is defined as front face and the casing with the perforation is defined as front casing). The front and rear casings are assembled to form a terminal seat product. To meet the actual requirement in a working site, it often takes place that different specifications of terminal seats with different numbers of perforations, (for example, two-perforation and five-perforation terminal seats) are needed. Accordingly, a manufacturer must manufacture different specifications of mold sets for manufacturing different sizes of front and rear casings with different numbers of perforations. As a result, the mold cost is quite high and a larger operation room is required.
In practice, the terminal seat or the front casing is marked with serial numbers such as A1, B2, C3, D4 in an encoding/printing process according to the number and sequence of the perforations of each terminal seat for a user to distinguish between the positions of the leads and know the connection relationship between the leads and the perforations of the terminal seat after the terminal seat and the leads are mounted. As known by those who skilled in this field, the manufacturer must prepare different sizes of stamping molds according to different specifications of terminal seat structures for receiving and fixing the terminal seats and performing the encoding/printing process. Accordingly, the stamping molds will have considerably larger volume.
As aforesaid, the conventional terminal seat has many shortcomings that need to be overcome. It is therefore tried by the applicant to provide an improved lead terminal seat structure, which has better stability and binding ability. Moreover, the mold cost and manufacturing cost for the lead terminal seat structure are lowered and the operation room for the lead terminal seat structure is minimized. The improved lead terminal seat structure has the following characteristics:    1. The improved lead terminal seat structure includes a terminal seat composed of a first insulation casing (left casing) and at least one second insulation casing (right casing) and a subsidiary sidewall. According to different specifications and conditions, one or more second casings can be assembled with the first casing and the subsidiary sidewall to form terminal seats with different specifications and different numbers of perforations for different applications. In contrast, in the conventional technique, it is necessary for a manufacturer to manufacture different specifications of mold sets for making different specifications of terminal seats with different numbers of perforations. This necessitates larger operation room and leads to increase of the manufacturing cost. The improved lead terminal seat structure overcomes the above problem existing in the prior art.    2. The improved lead terminal seat structure further includes a connection member for connecting the first and second casings (left and right casings) and the subsidiary sidewall. The connection member provides higher binding force and connection force for the first and second casings and the subsidiary sidewall. Accordingly, the first and second casings and the subsidiary sidewall of the terminal seat are more securely assembled with each other to bear the action force or external force applied to the cam operation lever for shifting the cam operation lever. Therefore, the terminal seat is protected from breaking apart or loosening and the leads can be more stably electrically connected with the terminal seat without swinging, poor contact or detachment.    3. The connection member provides higher binding force and connection force in the direction of the transverse reference axis for the first and second casings and the subsidiary sidewall. Accordingly, the first and second casings and the subsidiary sidewall of the terminal seat are more securely assembled with each other to bear the action force or external force applied to the operation lever and avoid lateral breakage or loosening due to the action force or external force.    4. The connection member has a lightweight and simple structure. Different sizes or lengths of connection members can be conveniently adaptively manufactured according to the specifications or the numbers of perforations of the terminal seats. The manufacturer can use a simple stamping mold to encode the connection member. In contrast, in the conventional technique, the manufacturer needs to prepare different sizes of stamping molds for different specifications of terminal seats. Such stamping molds have larger volume. The improved lead terminal seat structure overcomes this problem existing in the conventional technique.